| 摘要 |
PURPOSE:To permit copying at continuously varying magnifications and to improve resolving power and magnification accuracy by providing a parallel reflection optical system which uses a single projecting lens, and has a moving device for back focusing of said lens, a device for stopping the lens in a home position and a moving device for the purpose of changing optical path length and a device for stopping said system in its home position. CONSTITUTION:A device for a titled method is constituted of a light source device 1, a scanning system 2 which is mounted with microfilms and scans the same, a projecting lens 3, a position detector 7, a reflection optical system 4 which is movable for the purpose of changing the direction of the optical path and changing the length of the optical path, a postion detector 8 thereof, a mirror 5, a photosensitive drum 6, etc. First the system 4 is stopped on the high magnification side and in this state the back focusing of the lens 3 is moved and adjusted to adjust the resolving power on the drum 6 to the best condition. With the positions of the back focusing and the system 4 in this time as reference points, the lens is stopped in the home position and the magnification M0 in this time is measured; thereafter the system 4 is moved to move the back focus of the lens 3 and to adjust the resolving power again. The magnification M' in this time is determined. |
